In recent years biologically active materials, and especially enzymes, have been chemically and physically bonded to certain carriers, retaining the greater part of the biological activity. Such carrier bound enzymes are used repeatedly, can be filtered off easily from the substrate and are finding a wide-scale use in various applications in industry and research.
Supports used hitherto are certain synthetic polyamides, certain natural materials such as cellulose or derivatives thereof, other polysaccharides, polyacrylamide and the like.
Polyamides would of course have many advantageous properties as compared with the materials used hitherto, but due to the rather inert character of same as regards chemical reactivity, these have not been used for this purpose. Readily available polyamides have only terminal carboxy and amino groups available for such bonding and these are not adequate. Recently procedures have been described by which the binding capacity of nylons can be increased by mild hydrolysis, see Sundaram et al., (1970) FEBS Letters 10, 325 and Inman et al., (1972) Biochem.J. 129, 255. Such hydrolysis results in the partial breakup of the polymer into fragments of lower molecular weight, and this is a serious drawback.